This may help:

You can download the certificate (.crt file) to your /home/user/MyDocs/Downloads by connecting the phone via USB. Then use Filebox (get this file manager app from the Ovi Store) to locate the file. When you tap on the file, Filebox runs the associated app, which allows you to install the certificate. An Install button is shown; once you click it, the certificate is installed and you can see (and enable/disable) what it can be used to do. You can confirm that your certificate is installed by opening Settings > Security > Certificates and finding it in the list.

This is, however, where I hit a snag. I am trying to connect to my corporate Wi-Fi. I downloaded and installed the required certificate. When I go to the Wi-Fi connection form and click the "Select certificate" combo box, the certificate is not listed there. The list contains a single entry: "None." Any thoughts/suggestions?